The piston (Figure 2) has fluid on both sides. The gage pressure below the piston P1 = 30 kPa and the absolute pressure above the piston P2 = 100 kPa . What force F must be applied to the piston to keep it stationary? The diameter D = 5 cm . Neglect the magnitude of the force due to Patm acting on the rod relative to the magnitude of the force due to P2 acting on the piston. Express your answer in N to three significant figures. D

A piston having a cross-sectional area of 0.43 m2 is located in a cylinder containing water as shown in the figure below. An open U-tube manometer is connected to the cylinder as shown. For h1 = 72 mm and h = 134 mm what is the value of the applied force, P, acting on the piston? The weight of the piston is negligible. Piston Water Mercury P = i N

A manometer containing two oils is used to assess the pressure of air in a storage tank.  Given the configuration of the oils in the picture, calculate the pressure in the tank.  The density of air is negligible to the density of the oils (?oil1 = 1000 ??/m3; ?oil2 = 400 ??/m3 ). The height of oil 1 is 1 ?, and the height of oil 2 is 0.8 ?.  The atmospheric pressure is 98 ???. The manometer is ipen to the atmosphere.

A barge floating in fresh water (ρ = 1000 kg/m3) is shaped like a hollow rectangular prism with base area A = 650 m2 and height H = 2.0 m. When empty the bottom of the barge is located H0 = 0.55 m below the surface of the water. When fully loaded with coal the bottom of the barge is located H1 = 1.8 m below the surface. Find the mass of the coal in terms of the given data.